（以下英文部分及圖片皆來源於RealFlow官方文檔：http://support.nextlimit.com/display/rf2014docs/Calm+Fluid+Surfaces）
When a fluid is poured into a glass or any other container you will see an up and down motion for a certain amount of time. A little later, the fluid comes to rest and forms an even surface. RealFlow mimics this behaviour, but it can take some time before the fluid is totally calm. During this time you can observe the fluid sloshing and moving. One method is simply to sit and wait until the fluid has relaxed, but this can be a very time consuming task. It is much better to support this process with RealFlow's “k Speed” daemon. Please bear in mind that this approach is suited for standard particle emitters. Hybrido fluids do not have to be relaxed.
當液體被倒入杯子或其他容器中，你會看到液體在一段時間之內將上下波動。一段時間後，液體靜止下來並形成一個水平表面。RF可以模擬這種行爲，但在液體靜止之前需要一些時間。在這段時間裏你可以觀察液體的晃動。一種簡單的方法是坐下來並等待液體靜止，但是這有些浪費時間。更好的方法是使用RF的 “k Speed” daemon（速度控制場）處理這一進程。請記住該方法只適用於標準粒子發射器，混合液體沒必要靜止。
A sloshing fluid and its relaxed state created with the method described here.
使用以上介紹方法仿真的晃動液體和其靜止狀態
All scene elements can be added from RealFlow's “Edit” menu:
所有場景元素都可以在RF的“Edit”菜單中添加：
- Add > Emitters | Objects | Daemons
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RealFlow nodes can be moved, scaled, and rotated with the W, R, and E keys.
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Imported objects from SD files have to be unlocked before they can be transformed with Selected object > Node Params > Node > SD ↔ Curve
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Viewport perspective is changed with the 1, 2, 3, and 4 keys.
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Shading modes are toggled with the 7, 8, 9, and 0 keys.
The Relaxation Process（靜止過程）
To create a calm and even surface, please follow these steps:
爲創建一個靜止與水平表面，請進行以下操作:
Start the simulation without the influence of the “k Speed” and "Drag Force" daemons.
在不受“k Speed” 與"Drag Force" daemons影響的情況下開始仿真。
- Fill the object until the desired water level has been reached and let the simulation run for a few more frames.
- 填充容器直至達到所需水位，讓仿真多運行幾幀。
- Set the emitter's “Speed” parameter to 0.
- 將emitter的“Speed”參數設置爲0
- Create an initial state and activate “Reset To Initial State”; reset the scene.
- 創建一個初始狀態然後激活“Reset To Initial State”（重置到初始狀態），重置場景。
- Add a “k Speed” daemon.
- 添加“k Speed” daemon
- Node Params > k Speed > Limit & Keep > Yes
- Max speed > 1.0
- Max speed > right-click > Add key
- Shift the timeline slider to frame 200 (the fluid disappears).
- 將時間軸調至第200幀（液體不見了）
- Max speed > 0.01
- Max speed > right-click > Add key
- Reset (the fluid reappears).
- 重置（液體重現）
- Add a “Drag Force” daemon.
- 添加“Drag Force” daemon
- Under Drag Force > Drag Strength create two keys with values of 0 (f = 0) and 75 (f = 200).
- 在Drag Force > Drag Strength（阻力值）新建兩個值,第0幀值爲0，第200幀值爲75。
- Simulate. At frame 200 the fluid should be calm and relaxed.
- 仿真。在第200幀處液體靜止。
- Create a new initial state for your final simulation as described above.
- 按照以上所述爲最終仿真創建一個新的初始狀態。
- Reset.
- 重置
An initial state can be saved easily:
初始狀態很容易被保存：
- Make an initial state with Node Params > Initial State > Make Initial State.
- 通過Node Params > Initial State > Make Initial State創建初始狀態。
- Set “Use Initial State” to “Yes”.
- 將“Use Initial State”設爲“Yes”。（即設置使用初始狀態）
- Activate the “Reset To InitialState” option with a click on the triangle next to the “Reset” button.
- 點擊“Reset”按鈕旁邊的三角形激活“Reset To InitialState”選項。
- Optional: backup your previous data or apply a new export name for the emitter.
- 任選：備份之前的數據或爲emitter應用一個新導出名。
- Reset the scene to load the initial state at frame 0 (or any other specified frame).
- 重置場景以載入第0幀處的初始狀態（或其他指定幀處）。
- Simulate, using the initial state.
- 仿真，使用初始狀態。
This procedure will help you get an even fluid surface you can use as a starting point for a new simulation. Depending on the number of particles, this process can take a while. We therefore recommend disabling the viewport during simulation (Alt + D) or using the Command Line version:
以上過程可以幫你得到一個可以用作其他仿真開頭的水平液麪。基於粒子數量，運行需要一段時間。所以我們建議在仿真時關閉視口或使用命令行版本。
- Simulation button context menu > Command line